Substrate processing apparatus typically include a substrate support to support a substrate during processing. The substrate support may include a radio frequency (RF) electrode disposed proximate a substrate processing surface to receive RF current from an RF source. For example, the RF electrode may act as an RF return to ground or have the RF source coupled to the RF electrode. The RF electrode may be coupled to a rod, a wire, or the like to provide RF current to the RF electrode or to return the RF current to ground. The substrate support may further include a heater disposed proximate the substrate processing surface to heat a substrate when disposed on the substrate processing surface. However, the inventors have observed that thermocouples and AC power leads that are in the path of the RF return path are adversely affected by RF noise.
Thus, the inventors have provided an improved substrate processing apparatus.